Develop a model tumor system, including human cancers of breast, lung, colon, and ovary, grown in CBA mice deprived of T-lymphocytes and protected with syngeneic bone marrow; Examine various methods of transplantation; Investigate methods of assessing antitumor effectiveness; and Develop method comparing response of such tumor with response in patients receiving chemotherapy. Collect potential antineoplastic agents obtained from various sources in England. Submit these compounds to Chester Beatty Research Institute and NCI for evaluation by series of standard screening tests. Follow up active substances by means of procedures additional to standard NCI screening tests reverred to above.